To qualify, by "moving as quickly as possible" I meant that the mean speed should be high, and the peak speed low. I.e. better to have a clear road upon which traffic consistently does 20mph rather than one where it varies between zero and thirty, for example.
I'd argue that the "doctrine of modern urbanism" usually takes quite the opposite approach to what you suggest (possibly as an ill-advised reaction to the approach you describe being implemented in the past) by seeking to impede traffic flow as much as possible; with bollard, pinch-points, chicanes etc..
I'd also counter your last point with my own perspective as a driver, in that I can be trusted to drive at a sensible speed through residential areas, however being forced to stop for no reason other than some ill-conceived traffic calming crap really boils my p*ss.
On top of the pollution argument there's also that of necessary observation and road safety; especially relatively to cyclists if cars are constantly being forced to start and stop, or otherwise significantly modulate their speed.
As a driver, rider or resident I'd much rather use / be close to roads that have traffic flowing at a steady, constant speed than one where it's constantly stop-start.
Modern urbanism is about not impeding the flow of motorised traffic. The opposite of what you seem to think, in fact. Our towns and cities for the most part have been designed to allow as many private cars to journey from their start points to their destinations as quickly as possible, marginalising pedestrians and even more so, cyclists.
Drivers thus have the expectation their flow should not be impeded, whether it be by traffic calming, slower moving cyclists or junctions that force people to slow down further before you can commit or yield.
Growing up in a new town where all the junctions were designed with long sweeping curves and roudabouts were used in preference to traffic lights might be great for drivers who want to make swift progress, but it is terrible for pedestrians and cyclists. The net result is, that drivers when negotiating junctions don't expect to have to stop. They expect to go. And at rush hour (which means most of the day) pedestrians can struggle to safely negotiate the traffic.
When safely negotiating a junction, a driver should be prepared to stop and they should only proceed when they can see both their route into the junction and their route out of the junction is clear. Infrastructure should encourage drivers to do just that.
Further more, given that over half of journeys are less than 5 miles long, more priority should be given to pedestrians and cyclists in order to encourage people not to drive when it is not necessary. In residential and urban areas, it is drivers that should be marginalised.
Flowing traffic is better than stationary traffic, however maintaining traffic flow should not be at the expense of other transport modes. Given that average speeds across most towns and cities struggle to reach 12 mph, blanket 20 mph urban speed limits will make little overall drifference to overall journey times and reduce the pollution caused by acceleration and braking. As well as the noise created by motorised traffic.
